Indeed, many Bostonians are tired of the outdated, inefficient Central Artery that winds through the heart of downtown Boston. Originally designed to handle 75,000 vehicles per day, the Artery now carries 190,000.

But the green monster will eventually be laid to rest. As part of an ongoing 13-year highway project, the Central Artery highway will be placed underground. Construction for this public works conglomeration, known as the ``Big Dig,'' began in 1991.

It is a massive operation that includes a new tunnel under Boston Harbor to Logan International Airport. The price tag for the project is a hefty $7.7 billion. Eighty-five percent of it is being paid for with federal highway money, while the state of Massachusetts is picking up the rest of the tab. State transportation officials say the new highway system will relieve city congestion, open up 200 acres of open space, and create more than 15,000 new jobs for residents. `Historic opportunity'

So far, construction hasn't been too messy. Crews are working on utility relocation in the downtown area. And last week, the final steel segment of the tube for the new 1 1/2-mile tunnel, called the Third Harbor Tunnel, was put in place. Major tunnel construction for the downtown area is not expected to begin until next summer.

But it has been a bit of a bumpy ride for this road project. Neighborhood activists and environmental groups oppose a bridge-crossing plan. Downtown merchants complain of disruption, noise, dust, and rodents during construction. City commuters worry about traffic delays. Conservationists are concerned that promised plans to improve mass transportation will be delayed.

There is even a dispute over whether to name the new tunnel after Boston Red Sox baseball legend Ted Williams. Proposed by Gov. William Weld (R), the name will be decided by the state legislature once the tunnel is up and running.

One of the most recent controversies over the project concerns the design for the Charles River crossing. In 1990, environmentalists objected to the original plan, known as ``Scheme Z,'' which was a massive structure of twisting ramps and wide roads.

They charged that the design was too large, unsightly, and took up valuable parkland. Several lawsuits followed, and the plan was scrapped.

Earlier this month, Bay State Transportation Secretary James Kerasiotes selected a modified design. He hopes to secure federal and additional state approval by early next year before the new design can be built.

But environmentalists are threatening possible legal action. They say the plan is just as offensive a structure as the first. Calling it ``Son of Scheme Z,'' Robert Zimmerman, executive director of the Charles River Watershed Association, says the new design swallows up space planned for extending a river park.

``The fear is that any land under the bridge would be so overshadowed, it would be virtually impossible to create any kind of open space,'' he says.

Another concern is public transportation. Environmentalists brokered an agreement with the state in 1991 to have an array of mass-transit initiatives included in the project, such as the extension of railway and subway lines, creation of more car-pool lanes, and parking freezes.

But environmentalists worry that these measures will be low on the priority list as costs escalate. Only two years ago, the Central Artery project was slated as a 10-year, $4.9 billion effort.

``This is the last of the great 1950s highway projects,'' says Daniel King, spokesman for the Charles River Crossing Coalition. ``We can no longer continue to pave our cities to allow access to single-occupancy vehicles.''

Costly new design

Central Artery officials say the increased project cost is due to controversy over ``Scheme Z.'' The need to find an alternative design delayed the project by two years, Mr. Zuk says. The new design has fewer loop ramps and lanes than the original and ``is the most environmentally sound alternative possible,'' he says.

According to C. Kenneth Orski, president of the Washington consulting agency Urban Mobility Corporation, it is not uncommon for urban highway projects to be delayed and have costs increased over time.

He cites as an example the Century Freeway project in Los Angeles, which began in the 1970s but was only recently completed due to severe environmental impacts including the dislocation of several hundred residents.

``The Century Freeway has demonstrated how difficult it is to build urban freeways ... both in terms of its cost and also in terms of environmental impacts,'' he says.